OPN3 and acral lentiginous melanoma: On the basis of these promising findings, along the line of the ALM initiation and development from benign pigmented macule to malignant primary melanoma to lymph node metastasis, we performed the expression of OPN3 in junctional melanocytic nevi (JMN) and ALMs on the foot, and inguinal lymph node metastasis (ILNMs) from foot ALMs, as well as its association with clinicopathological features and prognosis of ALMs.